That’s according to the State Forest Service’s annual forest health report, which legislators received Wednesday.

Mountain pine beetles infested 752,000 new acres last year, but the growth slowed for the second consecutive year, said State Forester Jeff Jahnke.

The outbreak began 15 years ago in Grand and Summit counties.

“The infestation has pretty much ended in those particular places because they ate themselves out of house and home,” Jahnke said.

All the expansion last year happened on the northern Front Range, where the beetles have jumped from lodgepole pines into ponderosas.

But in worrying news for people in southern Colorado, another species of beetle is expanding faster.

Spruce beetles infested 262,000 new acres in 2011, an acceleration of the pace from 2010.

The spruce beetle outbreak began in 2002, and the beetles already have killed many of the mature spruce trees in the Weminuche Wilderness.

Until now, though, most of the 750,000-acre outbreak was in the high-altitude backcountry.

“We are concerned that it’s slowly but surely reaching down into those acres that are more accessible and privately owned,” Jahnke said.

The U.S. Forest Service is concentrating its efforts on threats to human safety posed by dead trees, said Maribeth Gustafson, acting regional forester for the Rocky Mountains.

The Forest Service’s strategy calls for removal of dead trees in the wildland-urban interface, as well as along roads and trails.

Gustafson asked for state legislators to help her “manage expectations” about the extent to which the U.S. Forest Service can clear the millions of acres of dead trees because of legal and budget limitations.

Colorado legislators and members of Congress have clamored for years for more funding for the Forest Service, and Gustafson sought to reassure lawmakers that even if the forest budget is declining, the amount of money set aside for beetle mitigation is stable.

“We’re continuing to emphasize this work in the region, so we can use a variety of funds that are perhaps at the expense of other programs dear to other constituents in the state,” she said.